The invention relates to a revolving door provided with driven door panels which are movably positioned around a central rotating element. A revolving door of this kind is known from DE-A-44 25 047, wherein each door panel has an individual drive.
The known revolving door is characterized in that as central rotating element a circular rotation shaft is applied around which four door panels rotate under the influence of separate linear driving motors.
Another known revolving door is characterized in that as central rotating element an elongated shaft is applied, one thing and another being arranged such that at both sides of said shaft there are side walls which together with the shaft form two passages through which the door panels can move.
A disadvantage of said known embodiments of the revolving door is that its dimensions, and in particular the side walls"" length of circumference, are determined by the circumstances. This is especially the case where the embodiment is provided with a central rotation shaft and the side walls have the form of circle segments. With the revolving door according to the prior art the dimensions of said side walls are by necessity such that during rotation of the door panels there is always at least one pair of door panels to block the free passage for the sake of draught exclusion. As a consequence, the diameter of the revolving door also determines the dimensions required for the side walls. It is the object of the invention to provide greater freedom of design while providing the possibility to guarantee draught exclusion independent of situational conditions with respect to the available dimensions of the revolving door and the surroundings in which it is to be used.
To this end the revolving door according to the invention is characterized in that the driving speed for each door panel is chosen on the basis of the position taken by said door panel in its path of rotation. By this surprisingly simple measure the positioning of the separate door panels can be adjusted to one another under all conditions of use such as to fulfil all the utilization requirements of the revolving door.
In a particular embodiment of the revolving door according to the invention each pair of door panels may be provided with an individual drive. The door panels forming a pair should then be arranged symmetrically in relation to one another and in relation to the central rotating element.
A revolving door according to the invention that is in operation distinguishes itself from a revolving door of the prior art by the fact that the door panels no longer have a uniform rotation speed, but that said rotation speed may vary during the rotation around the central rotation element. Desirably the drive speed of the door panels is then varied such that during normal operation there is always at least one pair of door panels forming a draught exclusion between the central rotating element and the side walls.
In a further aspect, the revolving door according to a preferred embodiment of the invention is characterized in that an input device is provided for indexing a panic position or a summer position, and that when the input device is activated, the drives of the door panels are equipped to move said door panels to, and maintain them in a position so as to provide a free passage.